xref: /dragonfly/sys/dev/misc/lpt/lpt.c (revision b40e316c)
1 /*
2  * Copyright (c) 1990 William F. Jolitz, TeleMuse
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This software is a component of "386BSD" developed by
16  *	William F. Jolitz, TeleMuse.
17  * 4. Neither the name of the developer nor the name "386BSD"
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
22  * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
23  * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
24  * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
25  * NOT MAKE USE OF THIS WORK.
26  *
27  * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
28  * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
29  * REFERENCES SUCH AS THE  "PORTING UNIX TO THE 386" SERIES
30  * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
31  * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
32  * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
33  * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
34  * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPER BE LIABLE
40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46  * SUCH DAMAGE.
47  *
48  *	from: unknown origin, 386BSD 0.1
49  *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
50  *	From Id: nlpt.c,v 1.14 1999/02/08 13:55:43 des Exp
51  * $FreeBSD: src/sys/dev/ppbus/lpt.c,v 1.15.2.3 2000/07/07 00:30:40 obrien Exp $
52  * $DragonFly: src/sys/dev/misc/lpt/lpt.c,v 1.10 2004/09/19 00:23:33 dillon Exp $
53  */
54 
55 /*
56  * Device Driver for AT parallel printer port
57  * Written by William Jolitz 12/18/90
58  */
59 
60 /*
61  * Updated for ppbus by Nicolas Souchu
62  * [Mon Jul 28 1997]
63  */
64 
65 #include "opt_lpt.h"
66 
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/module.h>
70 #include <sys/bus.h>
71 #include <sys/conf.h>
72 #include <sys/kernel.h>
73 #include <sys/uio.h>
74 #include <sys/syslog.h>
75 #include <sys/malloc.h>
76 
77 #include <machine/clock.h>
78 #include <machine/bus.h>
79 #include <machine/resource.h>
80 #include <sys/rman.h>
81 
82 #include "lptio.h"
83 #include <bus/ppbus/ppbconf.h>
84 #include <bus/ppbus/ppb_1284.h>
85 #include "lpt.h"
86 #include "ppbus_if.h"
87 #include <bus/ppbus/ppbio.h>
88 
89 MALLOC_DEFINE(M_LPT, "lpt", "LPT buffers");
90 
91 #ifndef LPT_DEBUG
92 #define lprintf(args)
93 #else
94 #define lprintf(args)						\
95 		do {						\
96 			if (lptflag)				\
97 				printf args;			\
98 		} while (0)
99 static int volatile lptflag = 1;
100 #endif
101 
102 #define	LPINITRDY	4	/* wait up to 4 seconds for a ready */
103 #define	LPTOUTINITIAL	10	/* initial timeout to wait for ready 1/10 s */
104 #define	LPTOUTMAX	1	/* maximal timeout 1 s */
105 #define	BUFSIZE		1024
106 #define	BUFSTATSIZE	32
107 
108 #define	LPTUNIT(s)	((s)&0x03)
109 #define	LPTFLAGS(s)	((s)&0xfc)
110 
111 struct lpt_data {
112 	short	sc_state;
113 	/* default case: negative prime, negative ack, handshake strobe,
114 	   prime once */
115 	u_char	sc_control;
116 	char	sc_flags;
117 #define LP_UNITMASK	0x03	/* up to 4 units */
118 #define LP_POS_INIT	0x04	/* if we are a postive init signal */
119 #define LP_POS_ACK	0x08	/* if we are a positive going ack */
120 #define LP_NO_PRIME	0x10	/* don't prime the printer at all */
121 #define LP_PRIMEOPEN	0x20	/* prime on every open */
122 #define LP_AUTOLF	0x40	/* tell printer to do an automatic lf */
123 #define LP_BYPASS	0x80	/* bypass  printer ready checks */
124 	void	*sc_inbuf;
125 	void	*sc_statbuf;
126 	short	sc_xfercnt ;
127 	char	sc_primed;
128 	char	*sc_cp ;
129 	u_short	sc_irq ;	/* IRQ status of port */
130 #define LP_HAS_IRQ	0x01	/* we have an irq available */
131 #define LP_USE_IRQ	0x02	/* we are using our irq */
132 #define LP_ENABLE_IRQ	0x04	/* enable IRQ on open */
133 #define LP_ENABLE_EXT	0x10	/* we shall use advanced mode when possible */
134 	u_char	sc_backoff ;	/* time to call lptout() again */
135 
136 	struct resource *intr_resource;	/* interrupt resource */
137 	void *intr_cookie;		/* interrupt registration cookie */
138 	struct callout	sc_callout;
139 };
140 
141 #define LPT_NAME	"lpt"		/* our official name */
142 
143 static timeout_t lptout;
144 static int	lpt_port_test(device_t dev, u_char data, u_char mask);
145 static int	lpt_detect(device_t dev);
146 
147 #define DEVTOSOFTC(dev) \
148 	((struct lpt_data *)device_get_softc(dev))
149 #define UNITOSOFTC(unit) \
150 	((struct lpt_data *)devclass_get_softc(lpt_devclass, (unit)))
151 #define UNITODEVICE(unit) \
152 	(devclass_get_device(lpt_devclass, (unit)))
153 
154 static void lptintr(device_t dev);
155 static void lpt_intr(void *arg);	/* without spls */
156 
157 static devclass_t lpt_devclass;
158 
159 
160 /* bits for state */
161 #define	OPEN		(1<<0)	/* device is open */
162 #define	ASLP		(1<<1)	/* awaiting draining of printer */
163 #define	EERROR		(1<<2)	/* error was received from printer */
164 #define	OBUSY		(1<<3)	/* printer is busy doing output */
165 #define LPTOUT		(1<<4)	/* timeout while not selected */
166 #define TOUT		(1<<5)	/* timeout while not selected */
167 #define LPTINIT		(1<<6)	/* waiting to initialize for open */
168 #define INTERRUPTED	(1<<7)	/* write call was interrupted */
169 
170 #define HAVEBUS		(1<<8)	/* the driver owns the bus */
171 
172 
173 /* status masks to interrogate printer status */
174 #define RDY_MASK	(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)	/* ready ? */
175 #define LP_READY	(LPS_SEL|LPS_NBSY|LPS_NERR)
176 
177 /* Printer Ready condition  - from lpa.c */
178 /* Only used in polling code */
179 #define	LPS_INVERT	(LPS_NBSY | LPS_NACK |           LPS_SEL | LPS_NERR)
180 #define	LPS_MASK	(LPS_NBSY | LPS_NACK | LPS_OUT | LPS_SEL | LPS_NERR)
181 #define	NOT_READY(ppbus) ((ppb_rstr(ppbus)^LPS_INVERT)&LPS_MASK)
182 
183 #define	MAX_SLEEP	(hz*5)	/* Timeout while waiting for device ready */
184 #define	MAX_SPIN	20	/* Max delay for device ready in usecs */
185 
186 
187 static	d_open_t	lptopen;
188 static	d_close_t	lptclose;
189 static	d_write_t	lptwrite;
190 static	d_read_t	lptread;
191 static	d_ioctl_t	lptioctl;
192 
193 #define CDEV_MAJOR 16
194 static struct cdevsw lpt_cdevsw = {
195 	/* name */	LPT_NAME,
196 	/* maj */	CDEV_MAJOR,
197 	/* flags */	0,
198 	/* port */	NULL,
199 	/* clone */	NULL,
200 
201 	/* open */	lptopen,
202 	/* close */	lptclose,
203 	/* read */	lptread,
204 	/* write */	lptwrite,
205 	/* ioctl */	lptioctl,
206 	/* poll */	nopoll,
207 	/* mmap */	nommap,
208 	/* strategy */	nostrategy,
209 	/* dump */	nodump,
210 	/* psize */	nopsize
211 };
212 
213 static int
214 lpt_request_ppbus(device_t dev, int how)
215 {
216 	device_t ppbus = device_get_parent(dev);
217 	struct lpt_data *sc = DEVTOSOFTC(dev);
218 	int error;
219 
220 	if (sc->sc_state & HAVEBUS)
221 		return (0);
222 
223 	/* we have the bus only if the request succeded */
224 	if ((error = ppb_request_bus(ppbus, dev, how)) == 0)
225 		sc->sc_state |= HAVEBUS;
226 
227 	return (error);
228 }
229 
230 static int
231 lpt_release_ppbus(device_t dev)
232 {
233 	device_t ppbus = device_get_parent(dev);
234 	struct lpt_data *sc = DEVTOSOFTC(dev);
235 	int error = 0;
236 
237 	if ((error = ppb_release_bus(ppbus, dev)) == 0)
238 		sc->sc_state &= ~HAVEBUS;
239 
240 	return (error);
241 }
242 
243 /*
244  * Internal routine to lptprobe to do port tests of one byte value
245  */
246 static int
247 lpt_port_test(device_t ppbus, u_char data, u_char mask)
248 {
249 	int	temp, timeout;
250 
251 	data = data & mask;
252 	ppb_wdtr(ppbus, data);
253 	timeout = 10000;
254 	do {
255 		DELAY(10);
256 		temp = ppb_rdtr(ppbus) & mask;
257 	}
258 	while (temp != data && --timeout);
259 	lprintf(("out=%x\tin=%x\ttout=%d\n", data, temp, timeout));
260 	return (temp == data);
261 }
262 
263 /*
264  * Probe simplified by replacing multiple loops with a hardcoded
265  * test pattern - 1999/02/08 des@freebsd.org
266  *
267  * New lpt port probe Geoff Rehmet - Rhodes University - 14/2/94
268  * Based partially on Rod Grimes' printer probe
269  *
270  * Logic:
271  *	1) If no port address was given, use the bios detected ports
272  *	   and autodetect what ports the printers are on.
273  *	2) Otherwise, probe the data port at the address given,
274  *	   using the method in Rod Grimes' port probe.
275  *	   (Much code ripped off directly from Rod's probe.)
276  *
277  * Comments from Rod's probe:
278  * Logic:
279  *	1) You should be able to write to and read back the same value
280  *	   to the data port.  Do an alternating zeros, alternating ones,
281  *	   walking zero, and walking one test to check for stuck bits.
282  *
283  *	2) You should be able to write to and read back the same value
284  *	   to the control port lower 5 bits, the upper 3 bits are reserved
285  *	   per the IBM PC technical reference manauls and different boards
286  *	   do different things with them.  Do an alternating zeros, alternating
287  *	   ones, walking zero, and walking one test to check for stuck bits.
288  *
289  *	   Some printers drag the strobe line down when the are powered off
290  * 	   so this bit has been masked out of the control port test.
291  *
292  *	   XXX Some printers may not like a fast pulse on init or strobe, I
293  *	   don't know at this point, if that becomes a problem these bits
294  *	   should be turned off in the mask byte for the control port test.
295  *
296  *	   We are finally left with a mask of 0x14, due to some printers
297  *	   being adamant about holding other bits high ........
298  *
299  *	   Before probing the control port, we write a 0 to the data port -
300  *	   If not, some printers chuck out garbage when the strobe line
301  *	   gets toggled.
302  *
303  *	3) Set the data and control ports to a value of 0
304  *
305  *	This probe routine has been tested on Epson Lx-800, HP LJ3P,
306  *	Epson FX-1170 and C.Itoh 8510RM
307  *	printers.
308  *	Quick exit on fail added.
309  */
310 static int
311 lpt_detect(device_t dev)
312 {
313 	device_t ppbus = device_get_parent(dev);
314 
315 	static u_char	testbyte[18] = {
316 		0x55,			/* alternating zeros */
317 		0xaa,			/* alternating ones */
318 		0xfe, 0xfd, 0xfb, 0xf7,
319 		0xef, 0xdf, 0xbf, 0x7f,	/* walking zero */
320 		0x01, 0x02, 0x04, 0x08,
321 		0x10, 0x20, 0x40, 0x80	/* walking one */
322 	};
323 	int		i, error, status;
324 
325 	status = 1;				/* assume success */
326 
327 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
328 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
329 		status = 0;
330 		goto end_probe;
331 	}
332 
333 	for (i = 0; i < 18 && status; i++)
334 		if (!lpt_port_test(ppbus, testbyte[i], 0xff)) {
335 			status = 0;
336 			goto end_probe;
337 		}
338 
339 end_probe:
340 	/* write 0's to control and data ports */
341 	ppb_wdtr(ppbus, 0);
342 	ppb_wctr(ppbus, 0);
343 
344 	lpt_release_ppbus(dev);
345 
346 	return (status);
347 }
348 
349 static void
350 lpt_identify(driver_t *driver, device_t parent)
351 {
352 
353 	BUS_ADD_CHILD(parent, 0, LPT_NAME, 0);
354 }
355 
356 /*
357  * lpt_probe()
358  */
359 static int
360 lpt_probe(device_t dev)
361 {
362 	struct lpt_data *sc;
363 
364 	sc = DEVTOSOFTC(dev);
365 	bzero(sc, sizeof(struct lpt_data));
366 
367 	/*
368 	 * Now, try to detect the printer.
369 	 */
370 	if (!lpt_detect(dev))
371 		return (ENXIO);
372 
373 	device_set_desc(dev, "Printer");
374 
375 	return (0);
376 }
377 
378 static int
379 lpt_attach(device_t dev)
380 {
381 	device_t ppbus = device_get_parent(dev);
382 	struct lpt_data *sc = DEVTOSOFTC(dev);
383 	int zero = 0, unit = device_get_unit(dev);
384 	int error;
385 	uintptr_t irq;
386 
387 	sc->sc_primed = 0;	/* not primed yet */
388 	callout_init(&sc->sc_callout);
389 
390 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
391 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
392 		return (0);
393 	}
394 
395 	ppb_wctr(ppbus, LPC_NINIT);
396 
397 	/* check if we can use interrupt, should be done by ppc stuff */
398 	lprintf(("oldirq %x\n", sc->sc_irq));
399 
400 	/* retrieve the ppbus irq */
401 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
402 
403 	if (irq > 0) {
404 		/* declare our interrupt handler */
405 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
406 						       &zero, irq, irq, 1, RF_SHAREABLE);
407 	}
408 	if (sc->intr_resource) {
409 		sc->sc_irq = LP_HAS_IRQ | LP_USE_IRQ | LP_ENABLE_IRQ;
410 		device_printf(dev, "Interrupt-driven port\n");
411 	} else {
412 		sc->sc_irq = 0;
413 		device_printf(dev, "Polled port\n");
414 	}
415 	lprintf(("irq %x %x\n", irq, sc->sc_irq));
416 
417 	lpt_release_ppbus(dev);
418 
419 	cdevsw_add(&lpt_cdevsw, LP_UNITMASK, unit);
420 	make_dev(&lpt_cdevsw, unit,
421 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d", unit);
422 	make_dev(&lpt_cdevsw, unit | LP_BYPASS,
423 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d.ctl", unit);
424 	return (0);
425 }
426 
427 static void
428 lptout(void *arg)
429 {
430 	device_t dev = (device_t)arg;
431 	struct lpt_data *sc = DEVTOSOFTC(dev);
432 #ifdef LPT_DEBUG
433 	device_t ppbus = device_get_parent(dev);
434 #endif
435 
436 	lprintf(("T %x ", ppb_rstr(ppbus)));
437 	if (sc->sc_state & OPEN) {
438 		sc->sc_backoff++;
439 		if (sc->sc_backoff > hz/LPTOUTMAX)
440 			sc->sc_backoff = sc->sc_backoff > hz/LPTOUTMAX;
441 		callout_reset(&sc->sc_callout, sc->sc_backoff, lptout, dev);
442 	} else {
443 		sc->sc_state &= ~TOUT;
444 	}
445 
446 	if (sc->sc_state & EERROR)
447 		sc->sc_state &= ~EERROR;
448 
449 	/*
450 	 * Avoid possible hangs due to missed interrupts
451 	 */
452 	if (sc->sc_xfercnt) {
453 		lptintr(dev);
454 	} else {
455 		sc->sc_state &= ~OBUSY;
456 		wakeup((caddr_t)dev);
457 	}
458 }
459 
460 /*
461  * lptopen -- reset the printer, then wait until it's selected and not busy.
462  *	If LP_BYPASS flag is selected, then we do not try to select the
463  *	printer -- this is just used for passing ioctls.
464  */
465 
466 static	int
467 lptopen(dev_t dev, int flags, int fmt, struct thread *p)
468 {
469 	int s;
470 	int trys, err;
471 	u_int unit = LPTUNIT(minor(dev));
472 	struct lpt_data *sc = UNITOSOFTC(unit);
473 	device_t lptdev = UNITODEVICE(unit);
474 	device_t ppbus = device_get_parent(lptdev);
475 
476 	if (!sc)
477 		return (ENXIO);
478 
479 	if (sc->sc_state) {
480 		lprintf((LPT_NAME ": still open %x\n", sc->sc_state));
481 		return(EBUSY);
482 	} else
483 		sc->sc_state |= LPTINIT;
484 
485 	sc->sc_flags = LPTFLAGS(minor(dev));
486 
487 	/* Check for open with BYPASS flag set. */
488 	if (sc->sc_flags & LP_BYPASS) {
489 		sc->sc_state = OPEN;
490 		return(0);
491 	}
492 
493 	/* request the ppbus only if we don't have it already */
494 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0) {
495 		/* give it a chance to try later */
496 		sc->sc_state = 0;
497 		return (err);
498 	}
499 
500 	s = spltty();
501 	lprintf((LPT_NAME " flags 0x%x\n", sc->sc_flags));
502 
503 	/* set IRQ status according to ENABLE_IRQ flag
504 	 */
505 	if (sc->sc_irq & LP_ENABLE_IRQ)
506 		sc->sc_irq |= LP_USE_IRQ;
507 	else
508 		sc->sc_irq &= ~LP_USE_IRQ;
509 
510 	/* init printer */
511 	if ((sc->sc_flags & LP_NO_PRIME) == 0) {
512 		if((sc->sc_flags & LP_PRIMEOPEN) || sc->sc_primed == 0) {
513 			ppb_wctr(ppbus, 0);
514 			sc->sc_primed++;
515 			DELAY(500);
516 		}
517 	}
518 
519 	ppb_wctr(ppbus, LPC_SEL|LPC_NINIT);
520 
521 	/* wait till ready (printer running diagnostics) */
522 	trys = 0;
523 	do {
524 		/* ran out of waiting for the printer */
525 		if (trys++ >= LPINITRDY*4) {
526 			splx(s);
527 			sc->sc_state = 0;
528 			lprintf(("status %x\n", ppb_rstr(ppbus)));
529 
530 			lpt_release_ppbus(lptdev);
531 			return (EBUSY);
532 		}
533 
534 		/* wait 1/4 second, give up if we get a signal */
535 		if (tsleep((caddr_t)lptdev, PCATCH, "lptinit", hz/4) !=
536 		    EWOULDBLOCK) {
537 			sc->sc_state = 0;
538 			splx(s);
539 
540 			lpt_release_ppbus(lptdev);
541 			return (EBUSY);
542 		}
543 
544 		/* is printer online and ready for output */
545 	} while ((ppb_rstr(ppbus) &
546 			(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
547 					(LPS_SEL|LPS_NBSY|LPS_NERR));
548 
549 	sc->sc_control = LPC_SEL|LPC_NINIT;
550 	if (sc->sc_flags & LP_AUTOLF)
551 		sc->sc_control |= LPC_AUTOL;
552 
553 	/* enable interrupt if interrupt-driven */
554 	if (sc->sc_irq & LP_USE_IRQ)
555 		sc->sc_control |= LPC_ENA;
556 
557 	ppb_wctr(ppbus, sc->sc_control);
558 
559 	sc->sc_state = OPEN;
560 	sc->sc_inbuf = malloc(BUFSIZE, M_LPT, M_WAITOK);
561 	sc->sc_statbuf = malloc(BUFSTATSIZE, M_LPT, M_WAITOK);
562 	sc->sc_xfercnt = 0;
563 	splx(s);
564 
565 	/* release the ppbus */
566 	lpt_release_ppbus(lptdev);
567 
568 	/* only use timeout if using interrupt */
569 	lprintf(("irq %x\n", sc->sc_irq));
570 	if (sc->sc_irq & LP_USE_IRQ) {
571 		sc->sc_state |= TOUT;
572 		sc->sc_backoff = hz / LPTOUTINITIAL;
573 		callout_reset(&sc->sc_callout, sc->sc_backoff, lptout, lptdev);
574 	}
575 
576 	lprintf(("opened.\n"));
577 	return(0);
578 }
579 
580 /*
581  * lptclose -- close the device, free the local line buffer.
582  *
583  * Check for interrupted write call added.
584  */
585 
586 static	int
587 lptclose(dev_t dev, int flags, int fmt, struct thread *p)
588 {
589 	u_int unit = LPTUNIT(minor(dev));
590 	struct lpt_data *sc = UNITOSOFTC(unit);
591 	device_t lptdev = UNITODEVICE(unit);
592         device_t ppbus = device_get_parent(lptdev);
593 	int err;
594 
595 	if(sc->sc_flags & LP_BYPASS)
596 		goto end_close;
597 
598 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
599 		return (err);
600 
601 	sc->sc_state &= ~OPEN;
602 
603 	/* if the last write was interrupted, don't complete it */
604 	if((!(sc->sc_state & INTERRUPTED)) && (sc->sc_irq & LP_USE_IRQ)) {
605 		while ((ppb_rstr(ppbus) &
606 		    (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
607 		    (LPS_SEL|LPS_NBSY|LPS_NERR) || sc->sc_xfercnt) {
608 			/* wait 1/4 second, give up if we get a signal */
609 			if (tsleep((caddr_t)lptdev, PCATCH,
610 			    "lpclose", hz) != EWOULDBLOCK) {
611 				break;
612 			}
613 		}
614 	}
615 	callout_stop(&sc->sc_callout);
616 	ppb_wctr(ppbus, LPC_NINIT);
617 	free(sc->sc_inbuf, M_LPT);
618 	free(sc->sc_statbuf, M_LPT);
619 
620 end_close:
621 	/* release the bus anyway
622 	 * unregistration of interrupt forced by release
623 	 */
624 	lpt_release_ppbus(lptdev);
625 
626 	sc->sc_state = 0;
627 	sc->sc_xfercnt = 0;
628 	lprintf(("closed.\n"));
629 	return(0);
630 }
631 
632 /*
633  * lpt_pushbytes()
634  *	Workhorse for actually spinning and writing bytes to printer
635  *	Derived from lpa.c
636  *	Originally by ?
637  *
638  *	This code is only used when we are polling the port
639  */
640 static int
641 lpt_pushbytes(device_t dev)
642 {
643 	struct lpt_data *sc = DEVTOSOFTC(dev);
644 	device_t ppbus = device_get_parent(dev);
645 	int spin, err, tic;
646 	char ch;
647 
648 	lprintf(("p"));
649 	/* loop for every character .. */
650 	while (sc->sc_xfercnt > 0) {
651 		/* printer data */
652 		ch = *(sc->sc_cp);
653 		sc->sc_cp++;
654 		sc->sc_xfercnt--;
655 
656 		/*
657 		 * Wait for printer ready.
658 		 * Loop 20 usecs testing BUSY bit, then sleep
659 		 * for exponentially increasing timeout. (vak)
660 		 */
661 		for (spin = 0; NOT_READY(ppbus) && spin < MAX_SPIN; ++spin)
662 			DELAY(1);	/* XXX delay is NOT this accurate! */
663 		if (spin >= MAX_SPIN) {
664 			tic = 0;
665 			while (NOT_READY(ppbus)) {
666 				/*
667 				 * Now sleep, every cycle a
668 				 * little longer ..
669 				 */
670 				tic = tic + tic + 1;
671 				/*
672 				 * But no more than 10 seconds. (vak)
673 				 */
674 				if (tic > MAX_SLEEP)
675 					tic = MAX_SLEEP;
676 				err = tsleep((caddr_t)dev, 0,
677 					LPT_NAME "poll", tic);
678 				if (err != EWOULDBLOCK) {
679 					return (err);
680 				}
681 			}
682 		}
683 
684 		/* output data */
685 		ppb_wdtr(ppbus, ch);
686 		/* strobe */
687 		ppb_wctr(ppbus, sc->sc_control|LPC_STB);
688 		ppb_wctr(ppbus, sc->sc_control);
689 
690 	}
691 	return(0);
692 }
693 
694 /*
695  * lptread --retrieve printer status in IEEE1284 NIBBLE mode
696  */
697 
698 static int
699 lptread(dev_t dev, struct uio *uio, int ioflag)
700 {
701         u_int	unit = LPTUNIT(minor(dev));
702 	struct lpt_data *sc = UNITOSOFTC(unit);
703 	device_t lptdev = UNITODEVICE(unit);
704         device_t ppbus = device_get_parent(lptdev);
705 	int error = 0, len;
706 
707 	if (sc->sc_flags & LP_BYPASS) {
708 		/* we can't do reads in bypass mode */
709 		return (EPERM);
710 	}
711 
712 	if ((error = ppb_1284_negociate(ppbus, PPB_NIBBLE, 0)))
713 		return (error);
714 
715 	/* read data in an other buffer, read/write may be simultaneous */
716 	len = 0;
717 	while (uio->uio_resid) {
718 		if ((error = ppb_1284_read(ppbus, PPB_NIBBLE,
719 				sc->sc_statbuf, min(BUFSTATSIZE,
720 				uio->uio_resid), &len))) {
721 			goto error;
722 		}
723 
724 		if (!len)
725 			goto error;		/* no more data */
726 
727 		if ((error = uiomove(sc->sc_statbuf, len, uio)))
728 			goto error;
729 	}
730 
731 error:
732 	ppb_1284_terminate(ppbus);
733 	return (error);
734 }
735 
736 /*
737  * lptwrite --copy a line from user space to a local buffer, then call
738  * putc to get the chars moved to the output queue.
739  *
740  * Flagging of interrupted write added.
741  */
742 
743 static	int
744 lptwrite(dev_t dev, struct uio *uio, int ioflag)
745 {
746 	unsigned n;
747 	int err;
748         u_int	unit = LPTUNIT(minor(dev));
749 	struct lpt_data *sc = UNITOSOFTC(unit);
750 	device_t lptdev = UNITODEVICE(unit);
751         device_t ppbus = device_get_parent(lptdev);
752 
753 	if(sc->sc_flags & LP_BYPASS) {
754 		/* we can't do writes in bypass mode */
755 		return(EPERM);
756 	}
757 
758 	/* request the ppbus only if we don't have it already */
759 	/* XXX interrupt registration?! */
760 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
761 		return (err);
762 
763 	/* if interrupts are working, register the handler */
764 	if (sc->sc_irq & LP_USE_IRQ) {
765 		/* register our interrupt handler */
766 		err = BUS_SETUP_INTR(ppbus, lptdev, sc->intr_resource,
767 			       INTR_TYPE_TTY, lpt_intr, lptdev,
768 			       &sc->intr_cookie);
769 		if (err) {
770 			device_printf(lptdev, "handler registration failed, polled mode.\n");
771 			sc->sc_irq &= ~LP_USE_IRQ;
772 		}
773 	}
774 
775 	sc->sc_state &= ~INTERRUPTED;
776 	while ((n = min(BUFSIZE, uio->uio_resid)) != 0) {
777 		sc->sc_cp = sc->sc_inbuf;
778 		uiomove(sc->sc_cp, n, uio);
779 		sc->sc_xfercnt = n ;
780 
781 		if (sc->sc_irq & LP_ENABLE_EXT) {
782 			/* try any extended mode */
783 			err = ppb_write(ppbus, sc->sc_cp,
784 					sc->sc_xfercnt, 0);
785 			switch (err) {
786 			case 0:
787 				/* if not all data was sent, we could rely
788 				 * on polling for the last bytes */
789 				sc->sc_xfercnt = 0;
790 				break;
791 			case EINTR:
792 				sc->sc_state |= INTERRUPTED;
793 				return(err);
794 			case EINVAL:
795 				/* advanced mode not avail */
796 				log(LOG_NOTICE, LPT_NAME "%d: advanced mode not avail, polling\n", unit);
797 				break;
798 			default:
799 				return(err);
800 			}
801 		} else while ((sc->sc_xfercnt > 0)&&(sc->sc_irq & LP_USE_IRQ)) {
802 			lprintf(("i"));
803 			/* if the printer is ready for a char, */
804 			/* give it one */
805 			if ((sc->sc_state & OBUSY) == 0){
806 				lprintf(("\nC %d. ", sc->sc_xfercnt));
807 				lptintr(lptdev);
808 			}
809 			lprintf(("W "));
810 			if (sc->sc_state & OBUSY)
811 				if ((err = tsleep((caddr_t)lptdev,
812 					 PCATCH, LPT_NAME "write", 0))) {
813 					sc->sc_state |= INTERRUPTED;
814 					return(err);
815 				}
816 		}
817 
818 		/* check to see if we must do a polled write */
819 		if(!(sc->sc_irq & LP_USE_IRQ) && (sc->sc_xfercnt)) {
820 			lprintf(("p"));
821 
822 			err = lpt_pushbytes(lptdev);
823 
824 			if (err)
825 				return(err);
826 		}
827 	}
828 
829 	/* we have not been interrupted, release the ppbus */
830 	lpt_release_ppbus(lptdev);
831 
832 	return(0);
833 }
834 
835 /*
836  * lpt_intr -- handle printer interrupts which occur when the printer is
837  * ready to accept another char.
838  *
839  * do checking for interrupted write call.
840  */
841 
842 static void
843 lpt_intr(void *arg)
844 {
845 	device_t lptdev = (device_t)arg;
846         device_t ppbus = device_get_parent(lptdev);
847 	struct lpt_data *sc = DEVTOSOFTC(lptdev);
848 	int sts = 0;
849 	int i;
850 
851 	/* we must own the bus to use it */
852 	if ((sc->sc_state & HAVEBUS) == 0)
853 		return;
854 
855 	/*
856 	 * Is printer online and ready for output?
857 	 *
858 	 * Avoid falling back to lptout() too quickly.  First spin-loop
859 	 * to see if the printer will become ready ``really soon now''.
860 	 */
861 	for (i = 0; i < 100 &&
862 	     ((sts=ppb_rstr(ppbus)) & RDY_MASK) != LP_READY; i++) ;
863 
864 	if ((sts & RDY_MASK) == LP_READY) {
865 		sc->sc_state = (sc->sc_state | OBUSY) & ~EERROR;
866 		sc->sc_backoff = hz/LPTOUTINITIAL;
867 
868 		if (sc->sc_xfercnt) {
869 			/* send char */
870 			/*lprintf(("%x ", *sc->sc_cp)); */
871 			ppb_wdtr(ppbus, *sc->sc_cp++) ;
872 			ppb_wctr(ppbus, sc->sc_control|LPC_STB);
873 			/* DELAY(X) */
874 			ppb_wctr(ppbus, sc->sc_control);
875 
876 			/* any more data for printer */
877 			if(--(sc->sc_xfercnt) > 0) return;
878 		}
879 
880 		/*
881 		 * No more data waiting for printer.
882 		 * Wakeup is not done if write call was not interrupted.
883 		 */
884 		sc->sc_state &= ~OBUSY;
885 
886 		if(!(sc->sc_state & INTERRUPTED))
887 			wakeup((caddr_t)lptdev);
888 		lprintf(("w "));
889 		return;
890 	} else	{	/* check for error */
891 		if(((sts & (LPS_NERR | LPS_OUT) ) != LPS_NERR) &&
892 				(sc->sc_state & OPEN))
893 			sc->sc_state |= EERROR;
894 		/* lptout() will jump in and try to restart. */
895 	}
896 	lprintf(("sts %x ", sts));
897 }
898 
899 static void
900 lptintr(device_t dev)
901 {
902 	/* call the interrupt at required spl level */
903 	int s = spltty();
904 
905 	lpt_intr(dev);
906 
907 	splx(s);
908 	return;
909 }
910 
911 static	int
912 lptioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *p)
913 {
914 	int	error = 0;
915         u_int	unit = LPTUNIT(minor(dev));
916         struct	lpt_data *sc = UNITOSOFTC(unit);
917 	u_char	old_sc_irq;	/* old printer IRQ status */
918 
919 	switch (cmd) {
920 	case LPT_IRQ :
921 		if(sc->sc_irq & LP_HAS_IRQ) {
922 			/*
923 			 * NOTE:
924 			 * If the IRQ status is changed,
925 			 * this will only be visible on the
926 			 * next open.
927 			 *
928 			 * If interrupt status changes,
929 			 * this gets syslog'd.
930 			 */
931 			old_sc_irq = sc->sc_irq;
932 			switch(*(int*)data) {
933 			case 0:
934 				sc->sc_irq &= (~LP_ENABLE_IRQ);
935 				break;
936 			case 1:
937 				sc->sc_irq &= (~LP_ENABLE_EXT);
938 				sc->sc_irq |= LP_ENABLE_IRQ;
939 				break;
940 			case 2:
941 				/* classic irq based transfer and advanced
942 				 * modes are in conflict
943 				 */
944 				sc->sc_irq &= (~LP_ENABLE_IRQ);
945 				sc->sc_irq |= LP_ENABLE_EXT;
946 				break;
947 			case 3:
948 				sc->sc_irq &= (~LP_ENABLE_EXT);
949 				break;
950 			default:
951 				break;
952 			}
953 
954 			if (old_sc_irq != sc->sc_irq )
955 				log(LOG_NOTICE, LPT_NAME "%d: switched to %s %s mode\n",
956 					unit,
957 					(sc->sc_irq & LP_ENABLE_IRQ)?
958 					"interrupt-driven":"polled",
959 					(sc->sc_irq & LP_ENABLE_EXT)?
960 					"extended":"standard");
961 		} else /* polled port */
962 			error = EOPNOTSUPP;
963 		break;
964 	default:
965 		error = ENODEV;
966 	}
967 
968 	return(error);
969 }
970 
971 static device_method_t lpt_methods[] = {
972 	/* device interface */
973 	DEVMETHOD(device_identify,	lpt_identify),
974 	DEVMETHOD(device_probe,		lpt_probe),
975 	DEVMETHOD(device_attach,	lpt_attach),
976 
977 	{ 0, 0 }
978 };
979 
980 static driver_t lpt_driver = {
981 	LPT_NAME,
982 	lpt_methods,
983 	sizeof(struct lpt_data),
984 };
985 
986 DRIVER_MODULE(lpt, ppbus, lpt_driver, lpt_devclass, 0, 0);
987